The invention relates to a hydrodynamic torque converter. From DE-OS 29 43 194 a torque converter is known having a lock-up clutch. With this known construction, two fluid connections between the torque converter and a pump are merely reversed when the lock-up clutch is engaged and disengaged. In one state, the lock-up clutch is open and the torque is transmitted completely via the torque converter and, in the other state, the lock-up clutch is closed and the torque is transmitted past the converter, for example via a torsional vibration damper, directly to the gearbox.